1. Field of the Invention
The present invention relates to a system, method, and program for determining a configuration of a logical array including a plurality of storage devices.
2. Description of the Related Art
In a Redundant Array of Independent Disks (RAID Array) disk storage system, a data set is stored across a plurality of disks. In certain RAID implementations, parity data for the data striped across a set of disks is generated and stored for use in data recovery if necessary. In the current art, a user may access a graphical user interface (GUI) RAID configuration tool to create a logical RAID array forming a RAID rank, also known as a span. A span is a group of disks on which a data set is striped across and parity data maintained for the data sets in the span group. For RAID 3 or 5, a span must have at least three hard disk drives, whereas a RAID 1 span requires a minimum of two hard disk drives. Data or parity written to each disk in a RAID span is referred to as a stripe, where a stripe comprises the consecutive sectors written to a single disk in the span. A stride is the collection of all the stripes written to all the hard disk drives in the span. Many systems limit the number of hard disk drives that can be assigned to a single span, such as eight or sixteen. If the user wants to use more than the maximum number of disks that can be assigned to a single span, then the user must define multiple logical arrays or spans to provide for more disks.
There is a need in the art for improved techniques for allowing users to define a logical array, presenting a single logical storage space to the user.